Painting German figures in WW2
The difference between Heer, Waffen-SS and Luftwaffe figures

Although not all the sculptors offer us these details, you can identify Wehrmacht from Waffen-SS by the positioning of the stylized eagle. For the Wehrmacht this was worn on the right breast, while the Waffen-SS wore it on the left sleeve (the design was also more pointed).
Luftwaffe ground troops also wore the eagle on the right breast, but it was not stylised.

While the design of the tunics didn't differ too much from that of the Heer, Waffen-SS troops never had the dark blue green collar, although (due to necessity) they sometimes wore (modified) Heer uniforms.

The Waffen-SS also tended to more often wear camouflaged equipment, like their typical pull-over smocks. The "Kharkov parka" is another piece of typical equipment. Their Panzer tunics were also slightly different, but more about that later.

Another difference might be found in the presence of a cuff-band. For the Waffen-SS this was worn on the left sleeve, for the Wehrmacht on the right sleeve. Campaign bands were always worn on the left sleeve however.

Disclaimer:
I am sure this article can be vastly improved upon, so I would invite anyone with superior knowledge to contact me.

Article Last Updated: 20 May 2014